tbuckley/cabot-search huggingface dataset:
OS10.4.A A macrophage-based drug delivery platform for glioma treatment
Authors: M Sun, M Bialasek, T Rygiel, M Król, M Weller, T Weiss
Journal: Neuro-Oncology (2022)

Abstract Background There is an urgent need for more effective treatment strategies against gliomas. At present, even though various drugs have potent anti-tumor activity in vitro, their application in vivo is limited by ineffective delivery and systemic toxicity. Therefore, novel strategies are needed to deliver these drugs effectively and safely to the tumor site. Here, we developed an adoptive transfer strategy against malignant brain tumors utilizing macrophages that are loaded with ferritin-protein cages containing drugs or other proteins and transfer these nanocarriers to cancer cells in vitro and in vivo. Material and Methods Live-time imaging, microscopy and flow cytometry were utilized to investigate the transfer of ferritin cages from loaded macrophages to human or mouse glioma cells. Co-cultures of glioma cells and macrophages loaded with ferritin-drug cages were used to study the anti-glioma activity in vitro and orthotopic immunocompetent mouse glioma models were used to study the anti-glioma activity in vivo. Affinity purification-mass spectrometry (AP-MS) was used to elucidate the mechanisms of transfer by characterizing the interactome of ferritin cages within macrophages and cancer cells. Results We observed a high transfer efficiency of ferritin-cages from loaded macrophages into human and mouse glioma cells in vitro in co-culture assays and confirmed the transfer from macrophages to glioma cells also in vivo upon intravenous or intratumoral treatment of GL-261 or CT-2A glioma-bearing mice. To study the anti-glioma activity with therapeutically active payloads, we loaded murine/human macrophages with ferritin cages carrying cytotoxic payloads. Co-culture of these loaded macrophages with murine or human glioma cells in vitro revealed a time- and concentration-dependent cytotoxicity to glioma cells. In vivo, intravenous or intratumoral administration of ferritin-drug protein cages was tolerated without toxicities and conferred a survival benefit in two orthotopic murine glioma models (GL-261 and CT-2A). Interactome studies of ferritin-cage-binding proteins revealed phagocytic and cytoskeleton re-arrangement pathways to be involved in uptake and transfer of ferritin-cages from macrophages to glioma cells. Conclusion This ‘Trojan Horse’ approach constitutes a promising platform to deliver cytotoxic drugs effectively and safely to gliomas and provides a rationale for clinical translation.
P02.09.B Valproic acid changes total DNA methylation level and influences temozolomide effect in glioblastoma cell lines
Authors: A Barciszewska, A Belter, P Glodowicz, M Naskret-Barciszewska
Journal: Neuro-Oncology (2022)

Abstract Background Valproic acid (VPA) is a first-line antiepileptic drug for glioblastoma (GBM) patients. There is also some evidence it improves the clinical outcome in those patients. However, the exact mechanism of VPA action is vague. Temozolomide (TMZ) is a first-line chemotherapeutic in GBM. Epigenetics offers a connection between genetic and environmental factors that influence the development of the disease. The best-characterized epigenetic mark is 5-methylcytosine (m5C) in DNA. The aim of that project is to show the effects of VPA administration on the total DNA methylation level. Material and Methods Using the nucleotide post-labeling method, we analyzed the total amount of m5C in DNA of GBM (T98G, U118, U138), cancer (HeLa) and normal (HaCaT) cell lines treated with VPA, and a combination of VPA and with TMZ. Results We adjusted the VPA doses to the ones achieved in the central nervous system during treatment. We observed dose-dependent changes in the total DNA methylation in neoplastic cell lines and the lack of such effect in a normal cell line. VPA alone produced a clear dose-dependent increase in total DNA methylation in GBM cell lines and scarce in the non-neoplastic cell line. In GBM cell lines, TMZ decreased the level of m5C. However, the exposition of GBM cells to the combination of VPA and TMZ caused an adverse synergistic effect resulting in DNA demethylation. The highest loss of m5C was observed at the highest concentration of TMZ (100 μM) and VPA (350 μM), after 3 h of incubation in the T98G cell line. Conclusion Total DNA methylation changes in glioma cell lines under VPA treatment suggest the new mechanism of that drug action and promote clinical implications for adjusting VPA and TMZ therapy in GBM patients. Our results show the potential and possible obstacles of the combined therapy of TMZ with VPA. Our experiments show that combined therapy with both drugs leads to total DNA hypomethylation. Therefore the conclusion would be to stop VPA administration during TMZ chemotherapy temporarily.
OS08.3.A Distinct systemic and tumor microenvironment immune landscapes discriminate across sellar tumor types and controls through a methylation-based deconvolution method
Authors: G Herrgott, K Asmaro, B Thomas, K Nelson, S Cazacu, L Hasselbach, A Transou, A deCarvalho, A Mukherjee, A Robin, I Lee, S Kalkanis, J Rock, J Rock, H Noushmehr, A Castro
Journal: Neuro-Oncology (2022)

Abstract Background Systemic (Sys) and tumor microenvironment (TME) immune milieus play a pivotal role in tumor development, outcome and immunotherapy response predictions across a variety of central nervous system tumors. Genome-wide methylation profiling can reliably discriminate and estimate immune cell proportions present in the blood and within the tumor and has not been reported across sellar tumor types (STT). Material and Methods We estimated cell composition in liquid biopsy (LB, serum/plasma) and tissue specimens from 42 STT collections (i.e., pituitary neuroendocrine tumors [PitNETs; n=37] and craniopharyngiomas [CP; n=5]), and 26 nontumor controls (LB: 11; Tissue: 15) using MethylCIBERSORT, a methylation-based deconvolution algorithm and established immune cell signatures as reference. LB methylation was profiled with EPIC array. Correlations between estimated cell proportions across sample sources were explored (Spearman). Immune cell proportion hierarchical k-means clustering was performed across tissue and LB specimens. Similarly, mean comparisons between and across sample types and subgroups of interest were performed [Non-parametric Kruskal-Wallis, Wilcoxon rank-sum tests; p&amp;lt;0.05]. Results We identified three immune-clusters across tissue specimens which distinguished controls (k3-cluster) from sellar tumor specimens (k1- and k2- clusters), primarily attributable to differential B-cell and monocyte proportions. Interestingly, a subset of PitNET and CP, belonging to the k2-cluster, presented a distinct immune profile compared to their K1-sellar tumor counterparts. Analysis of plasma-derived immune clusters revealed that PitNETs were distributed across four distinct immune patterns and CP clustered together with controls and a PitNET subset. One of the PitNET clusters was enriched with patients that died during follow-up and presented an enrichment of CD4-(including the regulatory subtype), CD8 and CD56-T and depletion of natural killer cells. Differences across serum- and tissue-derived clusters were present but less prominent than their plasma counterparts. No correlation between immune cell proportions across other clinicopathological features within each tumor type (sex, age, histotypes, invasion etc) was observed. Conclusion Our results suggest that PitNETs are characterized by differential TME and systemic immune subtypes which also distinguish these tumors from CP and controls. Additionally, distinct systemic immune composition between tissue and LB sources, more readily observed in plasma, suggest that the systemic response to the presence of the tumor is distinct from the immune response noted in the TME. Tumor immune subtyping may allow the stratification of STT according to immunotherapy response vulnerabilities.
OS09.4.A Cognitive functioning of patients with diffuse glioma during stable disease
Authors: M Gorter, J G Röttgering, V Belgers, M R van Lingen, P C De Witt Hamer, L Douw, M Klein
Journal: Neuro-Oncology (2022)

Abstract Background Glioma patients often experience cognitive problems, which are associated with decreased functional independence and health-related quality of life. However, the prevalence and nature of cognitive impairment in these patients is relatively underreported, particularly during stable disease. In this study we determine the prevalence of cognitive deficits and explore distinct cognitive profiles of patients with diffuse glioma at least two months after tumor treatment. Material and Methods A total of 112 patients (mean age: 43 years) without clinical or radiological progression with a grade II-IV glioma were included in this observational cohort study. Cognitive functioning was assessed in five cognitive domains (attention, information processing speed, verbal memory, working memory, and executive functioning). Cognitive impairment was defined as a z-score of 1.5 SD below that of healthy controls. Hierarchical cluster analysis was used to examine cognitive profiles. Results In total, 46 patients (41%) had cognitive impairment. More than one domain was impaired in 25 of these patients (54%). The domains were affected in decreasing order of frequency: working memory in 31%, information processing speed in 22%, attention in 19%, verbal memory in 12%, and executive functioning in 11% of the patients. A clustered heatmap revealed three prominent cognitive clusters with an increasing number of cognitive domains impaired. The first cluster displayed patients with only working memory deficits, patients in the second cluster also had deficits in information processing speed, and the last cluster showed patients with impairments across all domains. Conclusion Cognitive impairment is highly prevalent in patients with diffuse glioma during stable disease. Working memory and information processing speed are most frequently affected. Importantly, our analyses show evidence for three subgroups in cognitively impaired glioma patients. Working memory seems an important driver in cognitive impairment given the involvement in all subgroups.
P01.20.B Peroperative cognitive monitoring in patients with aphasia
Authors: S L Hartung, I M C Huenges Wajer, M J E van Zandvoort, P A J T Robe
Journal: Neuro-Oncology (2022)

Abstract Background Cognitive monitoring during awake glioma surgery provides the opportunity to increase the extent of resection while preserving cognitive functions. Preoperative language functioning often determines whether awake surgery can be performed since some form of communication with the patient is essential. However, as complex as it may be to perform intraoperative monitoring in patients with severe preoperative language disturbances, it is risky to assume that language disturbances are definite without functional perspectives. In addition, there are other cognitive functions that should be preserved. This study investigates to what extent cognitive functions can be monitored during awake surgery in the presence of preoperative language disturbances. Material and Methods Glioma data were collected in a single-centre consecutive study cohort of 186 patients who underwent awake brain surgery for either low-grade (WHO grade 1-2) glioma (40 percent) or high-grade (WHO grade 3-4) glioma (60 percent). Preoperative language disturbances were evidenced during preoperative neuropsychological assessment based on performances on the Boston Naming Test (N= 27) and Token Test (N=25). Intraoperative procedures were performed as part of clinical care. Results Preliminary results on the Boston Naming Test show that intraoperative testing with the use of at least one language test (picture-naming) is feasible in 80 percent of all patients with language disturbances. In those cases, a functional boundary of language functions is found in 85 percent during awake surgery. Monitoring of other non-language functions, such as working memory, inhibition, speech, motor functions and social cognition, provided functional boundaries in 25 up to 85 percent of patients with language disturbances. Postoperatively, cognitive functioning was improved in a significant number of patients. Conclusion Based on these preliminary results we conclude that preoperative language disturbances do not prevent from monitoring language functions as well as other cognitive functions during awake glioma surgery. In a larger cohort, more in-depth analyses will be performed on additional outcome measures (Token test, survival rate, post-surgery treatment) and postoperative functioning will be compared to a control group of patients without preoperative language disturbances. By investigating the potential of awake surgery in patients who are severely cognitively affected, we aim to increase the applicability of this method to improve neuro-oncological treatments and optimally maintain quality of life.
OS05.4.A Single-cell characterization of human GBM reveals regional differences in tumor-infiltrating leukocyte activation
Authors: P Schmassmann, J Roux, S Dettling, S Hogan, S Herter, M Bacac, T Shekarian, T A Martins, M Ritz, G Hutter
Journal: Neuro-Oncology (2022)

Abstract Background Clinical trials of systemic T cell checkpoint blockade in GBM patients showed only disappointing results. This may be attributed in part to the immunosuppressive components of the GBM immune tumor microenvironment (iTME). Therefore, major efforts have been undertaken to describe the GBM iTME on a single cell level. However, human data on the composition of the iTME in different tumor regions (contrast enhancing tumor center versus peripheral infiltration zone) remain scarce. Material and Methods Here, we performed high-depth single-cell RNA sequencing (scRNA-seq) on patient-matched biopsies from tumor center and the peripheral infiltration zone of five primary GBM patients. Additionally, peripheral blood mononuclear cells (PBMC) of the same patients were included in the analysis to explore the transcriptional changes occurring during tumor infiltration of circulating immune cells. Main findings of the transcriptional analysis were confirmed by flow cytometry. Results Through analysis of &amp;gt; 45’000 cells, we revealed a distinct regional transcriptional profile of microglia (MG) and monocyte-derived macrophages (MdM), a non-reactive/exhausted MG subcluster in the GBM iTME and an impaired interferon-response signature in the tumor-peripheral cytotoxic cell compartment. Comparing CD8+ T cells from the tumor periphery to PBMC-derived CD8+ T cells of the same patient revealed CX3CR1high and CX3CR1int CD8+ T cells with effector and memory phenotype, respectively, enriched in the PBMC but lacking in the tumor periphery. Tumor peripheral CD8+ T cells shared features with tissue-resident memory CD8+ T cells with exhausted effector functions. Conclusion Our analysis provides a large-scale dissection of GBM-associated cell types complemented by patient-matched PBMCs, serving as a high dimensional reference map of the human GBM iTME.
P03.03.A STEREOBRAIN: Stereotactic radiosurgery versus whole-brain radiotherapy in patients with 4-10 brain metastases - a non-randomized controlled trial
Authors: M Niyazi, R Bodensohn, A Kaempfel, R Forbrig, S Garny, S Corradini, C Belka
Journal: Neuro-Oncology (2022)

Abstract Background Since the JLGK0901 study described non-inferiority of stereotactic radiosurgery (SRS) of 5-10 compared to 2-4 brain metastases in 2014, it has been widely discussed if SRS should replace whole brain radiotherapy (WBRT) in 5 - 10 brain metastases though lacking randomized evidence. At our department, WBRT has been the treatment of choice in 4-10 brain metastases until 2017. This paradigm was entirely changed to include patients within the STEREOBRAIN trial (DRKS00014694). We designed this prospective controlled single arm trial to systematically introduce SRS to 4 to 10 brain metastases comparing this new treatment regimen with the former approach. We aimed at showing a survival benefit of this novel treatment paradigm. Material and Methods Inclusion criteria were 4-10 brain metastases, largest diameter 2.5 cm, all histologies except SCLC, germ cell tumors, lymphoma, and ECOG ≤ 2. The retrospective WBRT cohort was identically selected from consecutive patients from 2012 to 2017 in a 1:2 fashion. At a significance level of 5%, a total number of 99 events (deaths) across the two groups allows to detect an increase in median OS from 6 months (retrospective WBRT cohort) to 11 months (SRS) considered clinically relevant (and corresponding to a hazard ratio of 0.55 assuming exponential distributions of survival times within groups) with a power of 80%. Propensity-score matching was performed to take confounders into account given the inherent bias caused by different treatment periods. Multiple brain mets SRS was performed using a single-isocenter technique. Results Patients were recruited from 2017 - 2020 and end of F/U was July 1st 2021. Forty patients were recruited to the SRS cohort and 70 patients were eligible within the WBRT cohort (81 events altogether). Median follow-up, OS and intracranial progression free survival were 21.6 months (95%-CI 19.8-NA), 10.4 months (95%-CI 9.3-NA) and 7.1 months (95%-CI 3.9-14.2) for the SRS-cohort, and 61.4 months (95% 54.6-NA), 6.5 months (95%-CI 4.9-10.4) and 5.9 months (95%-CI 4.1-8.8) for the WBRT-cohort, respectively. The Cox-model yielded a trend for improved survival within the SRS-cohort, HR 0.65 (95%-CI 0.4-1.1); p=0.076. After optimal propensity score matching, OS was significantly superior for the SRS-cohort (HR 0.53 (95%-CI 0.32-0.86), p=0.01). No grade III toxicities were observed in the SRS-cohort. Conclusion Despite all limitations of a historical control and missing the target number of events, there was a clear signal of improved survival with SRS compared to WBRT for patients with 4-10 metastases. Whether adapted WBRT (hippocampal sparing, simultaneous integrated boost) or SRS is to be preferred needs to be investigated in the future.
OS08.6.A Novel role of ARF4-mediated retrograde trafficking as a driver of chemoresistance in GBM
Authors: S Budhiraja, S Baisiwala, E Perrault, S Cho, G Dara, K Nandoliya, A Zolp, L Chen, C Dmello, C Park, A Sonabend, A Ahmed
Journal: Neuro-Oncology (2022)

Abstract Background Glioblastoma (GBM) is the most common type of adult malignant brain tumor, with a median survival of only 21 months. This is partly due to the high rate of resistance to conventional therapy, including temozolomide (TMZ), leading to recurrence rates close to 100%. To identify the unknown genes driving the development of this resistance, we performed a genome-wide CRISPR knockout screen comparing a DMSO-treated population with a TMZ-treated population over 14 days. Results showed substantial enrichment of ~200 novel genes, including a previously unstudied gene ARF4—involved in retrograde trafficking to the nucleus. Here, we set out to characterize the mechanism by which ARF4 may be acting to promote chemoresistance. Material and Methods A whole-genome CRISPR-Cas9 sensitivity screen as well as a variety of in vitro and in vivo experiments, such as live-cell imaging, cell viability assays, and western blotting were conducted. Results Initial investigation into ARF4 showed significant elevations in expression at RNA and protein levels (p&amp;lt;0.05) in recurrent patient tumors, as well as a significant survival benefit in patient datasets when downregulated (p&amp;lt;0.05). Knocking out ARF4 resulted in significantly heightened sensitivity to TMZ in multiple GBM patient-derived xenograft lines and extended survival compared to the controls (p&amp;lt;0.01) in vivo. Further investigation via live-cell imaging of transferrin receptors, a retrograde transport marker, revealed that ARF4-knockdowns significantly inhibited retrograde trafficking, while ARF4-overexpressions resulted in an untenable increase in retrograde trafficking in vitro. This effect was also seen in TMZ-treated cells, which displayed enhanced trafficking dynamics, suggesting that ARF4-mediated retrograde trafficking is elevated during therapy to drive nuclear localization of key chemoresistance-promoting factors. We then performed an unbiased proteomics screen to identify which genes were being uniquely transported to the nucleus as a product of ARF4-mediated retrograde trafficking, which revealed enrichment of the EGFR signaling pathway in particular. Validation experiments confirmed a decrease in EGFR trafficking and nuclear EGFR expression in ARF4-knockdowns and an increase in EGFR trafficking and nuclear EGFR expression in ARF4-overexpression and TMZ-treated GBM cells. Furthermore, nuclear DNA-PK, a DNA repair protein known to be transcriptionally activated by EGFR, was similarly found to be downregulated in ARF4-knockdown conditions and elevated in ARF4-overexpression and TMZ-treated conditions. Conclusion: Here, we show that ARF4 may be responsible for promoting chemoresistance through altered retrograde trafficking of EGFR specifically. Thus, our study has yielded a promising and novel therapeutic target for GBM, a disease desperately in need of new therapeutic strategies.
OS09.5.A The experience of interval scans for adults living with primary malignant brain tumours
Authors: S Rudkin, T C Booth, K Absolom, G Latchford, S C Short, F W Boele
Journal: Neuro-Oncology (2022)

Abstract Background People living with primary malignant brain tumours (PMBT) face a complex and unpredictable illness. Throughout the disease course they undergo various treatments and follow-up with regular interval scanning. There are potential costs and benefits to interval scanning, however there is no high-quality evidence to suggest interval scanning is beneficial or whether scans alter outcomes of importance for people living with PMBTs. Yet, interval scanning may exacerbate issues such as uncertainty and anxiety - which impacts on patient quality of life. The aim of this study was to gain an in-depth understanding of how adults living with PMBTs experience and cope with interval scanning. Material and Methods Twelve patients with a diagnosis of PMBT (glioblastoma n=10; astrocytoma grade 3 n=1; solitary fibrous tumour of the dura grade 3 n=1) under the neuro-oncology teams at Leeds Teaching Hospital NHS Trust and King's College Hospital NHS Foundation Trust took part in the study. They were interviewed remotely about their experiences of interval scans, following a semi-structured interview guide. An abbreviated version of a constructionist grounded theory approach was used to analyse data. Results Five main themes were generated from the data: ‘Living with a PMBT’, ‘Interval scanning: the difficult times’, ‘MRI scan: accepting the discomfort’, ‘Waiting for results: coping with the uncertainty’ and ‘Results: providing some certainty in uncertainty’. Although most participants found interval scans uncomfortable, they accepted that they were something that they had to do and were using various coping methods to get through the MRI scan. All participants said that the wait between their scan and results was the most difficult part. Despite the difficulties they experienced, all participants said that they would prefer to have interval scans than wait for a change in their symptoms. Most of the time, scans provided relief, gave participants some certainty in an uncertain situation, and a short-term sense of control over their lives. Conclusion The present study shows that interval scanning is important and highly valued by patients living with PMBT. Although interval scans are anxiety provoking, they appear to help people living with PMBT cope with the uncertainty of their diagnosis.